Transmitting apparatus for electric telegraphs



Apr. 24, 1923. 1,452,527

L. M. POTTS TRANSMITTING APPARATUS FOR ELECTRIC TELEGRAPHS original Filed Dec, 14, Mais'A A4 sheets-sheet 1 C i .0 A V///I'11111111111."IIIIIIM/ v I IN VEA/TOR. y

W Q? W Aom L. M. POTTS TRANSMITTING APPARATUS FOR ELECTRIC TELEGRAPHS orignal'Fned'De'c. 14, 1915 4 sheets-sheet 2 E@ E'A :ET E

l ai@ 141.09m 21.2.5.1.r l l l B'Ymfgmm/ A TTORN/fy.

Apr. 24, 1923. 1,452,527

L. M. PoTTs TRANSMITTING IVPPARATUS FOR ELECTRIC TEHJEGRAPFIS Y original Filed Dec. 14,{1915 4 Sheets--Sheet 5 A TTORNEY. f.

Api. 24,1923.- 1,452,527

' `L. M. POTTS TRANSMITTING APPARA'TUS FOR ELECTRIC TELGRAPHS original Filed Dec. 14, 1915 4.sheets-sheet 4 am@ am. 2a, raza TO .AMERICAN TELEPHONE' AND TELE CORIORATION F 1J EW YORK.

frTEs- Lot'rr's in. ro'rrs, or BALTIMORE, MnRYLANl-J, AssrGNon', BY mism: AssmNMENfrsfcmu COMPANY, or NEW YORK, N. Y., A

TRANSMITTING .jA'PPARATUS FOR ELECTRIC TELEGRAPHS.

Original 'application led December 14, 1915, Serial No. 66,830. Patent No. 1,Z'i0,`669,l dated Herck 8,

1921. Divided'and this 'application led February 6, -1920. -Serial'lo. 356,615.

To all wliomitmay concern:

lie it known that I, LOUIS M. Po'rTs, a

ycitizen oi the United States of America, residing at Baltimore, "State of Maryland, s`

.have invented certain .new and useful Imjfl rovements Ain Transmitting Apparatusfor fisffa specification.

f f. Thisinvention relatestotransmitting ap-, paratus in which the operation of.'the re-.. spect-ive. character `keys v1s translated lnto' eleptric'al .impulsesfthroug'h theaction of aV motor-driven mechanism.

board.

` An object of theinvention is the provision.

.of a positively-acting transmitting appara-` `Vtus controlled by anyr one-of a plurality of.'

keys for, initially setting such transmitting a` Xaratus into operation.

nother obJect is thvv provision of autoinatic means whereby the transmitting ap-vparatus may be controlled by an impulse of a particular character. e `he present application is a division of the SubJect matter embodied in an applica- `ticn filed December 14, 1915, Serial No.V 66,830, now Patent No. 1,370,669 of March s, 1921.

The invention will be described with reference to the accompanying drawings where- Fig. 1 isa vertical section of the machine showing the gears and a section of the key- Fig. 2 shows how Springl pressure is applied to the key levers.

Fig. 3 is a vertical section-showing 'the timing mechanism and other parts.

Fig. 4 shows the starting mechanism. Figs. 5, 6 and 7 show the magnet armature.

Fig. 8 is a current diagram indicating two of the signals.

Figs. 9 and 10-show the transmit-ting con tact and associated parts.

Fig. 11 shows the lockingr device for the keys. l

Figs. 12 and` 13 show the mechanism for sending the start impulse.

' Fig. 14 shows the timing mechanism,l escapement, clutch and associated parts.

. Fig. 15 is a detail of the escapement clutch and cams. v

' tri ger. y e y i i i igs..2 0 and 20a show the relation of the' lectric Telegraphs, of whlch the following.

Fig. 16 is a detail of the slow start sleeve. Fig. 17 is a detail of the thrust bearing between the slow start sleeve and cam shaft.

Figs. 18

cams ,on the` escapement shaft;

Vthe escapement shaft.A

line.. Y, A .,.Fi`g..23 is a,detail of part of the moto cut-off. f

motor cut-off. y V

The transmitting and signals.

The transmitting mechanisml in the form shown in the accompanying drawings comprises, amongst other parts, a keyboard Iconsisting of-a plurality' of key levers 1, pivottransmittedand are preferably arranged ac- -with cams 8 on said bars. To lshirt elements in various combinationsinthis way is well known in theart, so need not be further described here.

The transmissionv here Aemployed is based on the five unit or Baudot code, by which is meantthat each signal interval is divided into five unit impulse periodswhich we call the a, b, c, d andyeimpiirperiods, the signals being formed by cqmbining impulses Fig. .21 shows the relation ofthe cams ori' Fig. 24 is anrelectricalrdagram of the and 19 are views of the slow start Fig. 22`-is an electrical diagram offthe corresponding respectively to these periods l I as indicated, for example, in Fig. 8, where two complete signals are shown, one made upof a combination of the b and c imf uses, and another of the c and e impulses. hese lare the code impulses. For each sigin greater detail later.

` has a cam corresponding to cams Sfonv its cam faces which send lower edge for eachl key lever. I

The key levers are returned to normal under the action ot individual comprerssio'n springs 9, and the slide bars .66@ Aare returned `by the key levers engaging cam faces 1.0 slanting inan opposite direction Jfrom the the slides forward. On the operation ot' any key or the space bar, start slide 6 will be shifter to the right (Fig. 10). This imparts angular movement to a start lever 11, tulcrumiaedon a stationary supporting bracket 1.2, and engaging at its lower end a slot in the upper edgey otstart,r

slide 6. The upper end of lever 1,1 normally4 lies behind a -toe 13 on.` the lower end ot a lever 14, as in Fig.- 12, so as to cock the lower end of the latter lever outwards, or to the right, against the tension of a.spring 15. \Vhen start lever 11 is rockedv by slide6 on the depression of a key, its upper end will be thrown Jfrom behind toe 13, thus permitting spring 15 to pull the lower end ot lever 14 to ,the lett, asin Fig. 13.` When this'occurs, an offset or lip 16 on lever 14 willengage andcarry to the lett the lower end of a lever 17. Thislatter lever has a cam or shoulder 1 which, in the normal position of the parts, rests, as shown in Fig. 12, against the end of a cam 19,' so that when the lower end of said lever is thrust to the left (Fig. 10), it will turn on said cam as at fulcrum, its upper end being thrust to the right. The upper end of lever 17 is in constant engagement with a horizontal har 20 fast to a plunger' 21 slidably mounted in a tube 22 rigidly mounted in a block 23 of insulating `material rigidly secured to the selector trame. The outer end of this plunger is provided with an insulating tip 21 against which is held a contact lever 24 under constant tension of a' spring 25. Fast to one tace` of lever 24 -is a spring 24 .to\

which is rigidly secured a contact 26 which passes through an opening in lever 24 and is adapted to make andbreak contact with an adjustable stationary contact 27. The reason for mounting contact 26 on spring 24 is' to permit the lever 24 to move towards contact 27 after contact 26 has engaged contact 27, to prevent jamming. The movement of lever 17 to the right (Fig. 13) as deand between the e impulse ot scribed, acts through bar 2O to send contact 26 into engagement with contact 27, and to thus transmit the start impulse. lit will not be necessary here to describe the electric circuit of-tliis impulse further than to say that the contacts 26and 27 may he considered in a circuit which includes an electromagnet 28 (see Fig. Magnet 2S, on

:being energized bythe start impulse, will pull up its 'armature 29', against tension of spring 30. whereupon an extension 31 (Figs. 5-7) tast on said armature and normally lying beneath a downwardly extending toe 32 (see Figul) of a lever 33, will cause said lever. acting against an offset 34 on a vertically movable stop slide 35, to remove the lower end of the latter from engagement with a stop member 36 fast to a balance 37, and release the latter. whereupon it will oscillate under the control ot balance spring 38. The oscillation of this balancecontrols. through the medium of an anchor 39 and escape wheel 40, the step-by-step movement of a shatt 41. Thisshatt carries, tast thereon, a starting cam 19 and others to be presently described.

The balance'and escapement timing mechanism in substantially the torm herein shownv and described, is described and claimed in Patent No. 1.229,201, issued June 5, 1917.l so need not here be gone into in greater detail. l

Lever 35 is operated by armature extension 31 against the tension of a spring 42 and is held up, out of the path of stop 36.

until shaft 41 has made siv steps or a halt revolution, by an oitset or arm 43 on said lever resting upon the periphery of a cam 44, the high part of which holds said lever up as described, while two diametrically opposite drops 45 and 46 allow said stop slide to return under the action ot a spring 42 to the path of stop 36 in order to stop the oscillation of the balance at the end ot a signal interval which, in this machine. corresponds to the time ot a halt revolution of shaft 41, said-shaft making siX equal steps for each sucl. period. one tor the start impulse and five for the code impulses. Cam 44 is mounted fast on shaft 41.

Shaft 41 is power driven in the 'following I way: Mounted on the back of thc trame of the machine is a continuously operating electric motor 47, driven trom any desired local source of current (see Fig. l). Through a reduction gear, motor 47 continuously' drives gear 5.5.

Gear 5 5 is in constant mesh with a gear 62 (see Fig. 1) which imparts power to escapc-.

ment shaft 41 through a friction drive shown most clearly in Fig. 15. Gear 62 is tast on a bushing 63 adapted to rotate on a collar 64 having a circular periphery', but a square bore, the latter adapted to fit square shaft 41 and turn therewith. Near the outer face passes so as to form a positive drivingcon-g ,ne'ction Between this disc 65 and the web of. gear 62 is a oat'ingber disc 66 which may rotate either with gear 62 or with disc '651-' Disc 65 -is slidable longitudinally of i. shaft 41 and is forced towards gear 62 under tension of a spring 67 .1 The thrust 'of gear 62 to the left. (Fig. 15)A is taken up through ball thrust bearing 68 and parts to be later described. Plates 69 and 70 are-for-retaining in the clutch asupply of graphite grease or other lubricant.- For the present we are not concerned wththe other parts of this clutch` shown on the leftofgear 62 in Fig. 15.

From the description which has preceded, itl will be recalled that shaft 41 isnormally held against rotation. Notwithstanding this, gear 62 rotates continuously, but when slide is released from stop 36, shaft 41;,will rotate from the friction created between gear 62, and discs 65 and66 The code impulses Ato form the signals are transmitted by closing contacts 26-27 at times corresponding to 'the unit impulse periods of a signal interval, and this is effected by causing a series of five transmitting levers 71a, 71", 71, 71d and 71e, to act upon universal bar 20 in combinations corresponding to the signals to be transmitted. These transmitting levers, as well 'as levers 14and 17 all swing upon a common fulcrum 72 andmove in individual guide slots in -two cross bars 73 and 74`rigidly secured between two side' members 7 5 and 76 'of the selector frame.

While levers 71t-71c may turn on ulcrum 72 as a pivot, their upper ends may', y by means of a slot 77 in each, travel longitudi-- nally on said fulcrum. Each lever, h'cwever, is at all times under tension of an individual spring 78 which normally holds it in the position shown in Fig. 9 with the fulcrum rod 7 2 against the closed end of slot 77. Now, if pressure be applied to' any one or more of these levers at a point about ona level with and in the direction of. the straight arrow, Fig. 9, such lever 4being -restrained at its upper cndby spring 78 will turn on rod 72, and its lower end will swing to the right, assuming that its lower end is not restrained from this movement. If, however, the lower end of such lever is positively locked against such movement, the upper end of the lever will swing to the right against the tension of spring 78, and,`acting 'through bar 2Q, will send contact 26 into engagement with contact 27. The selective operation of levers 71"-71e consists in restraining the lower ends of'coinbinations of these levers against movement to the right Eig. 9 when power is: applied to them asnstated. The mechanism for applying saidp'ower comprises five cams 79a,7 9"," 79, 79- a-nd 79" `mounted'vfastfon shaft 41 and angularly displaced around the.-

cated in the same vertical plane lwith its corresponding `lever. of the series 715-716,A

axisof said shaft one twelfthvof a circum#V ference (see Figs.-20.and-20a),.andjeach.lo

and in such relation thereto that as-shat 41 rotates, theends of-these cams will engage" with cam projections l80 o n the yrespective i I levers'insuch' manner as to eXertforce on the levers inthe direction ofthe straight ar-i row Fig. 9. As shaft 41 'rotatesfstep-by-step,

these cams will therefore acto n levers 71E-71 successively, and these -camsare of such length that any'one of themfwill `elose contacts 26, 27 for an interval corresponding to a unit impulse-period. y

79 and is vstaggered one twelfth oa-circumference from cam 79." on shaft 41, and occupies the Aangular v position intermediate 'ofV cams 79a and 79.

Cam 19 is identical in shape to cams 7 93- aov as described, comprises' a series of five levers 81,81", 81C, 81d and 81","'similar to start lever 11,and fulcrumed individually upon bracket 12 to turn in a lane atri ht langlesto thep i movement of levers. 71- 1. The upper end of each lever vof the series 3P-81e normally liesforward of and `just to one sideof a corresponding lever of the'series 71a-71e,

so that by shifting the upper ends of any of the levers`81"'**-81e the proper distance to the'left; Fig. 10, will be brought in front of f' the `lower end of its corresponding lever of the series 713-712 thereby acting asa stop Lo positively lock the movement of said evers as described. Levers 811-81e are thus operated in' the desiredr combinations, by their .lower ends engaging'fwith individual slots each in a corresponding'slide bar of the series (Sa-6e, so that by shifting these bars in` combinations, corresponding levers 81- .81 will operate.

The slow start of; Zag prod/:wing mechanism,

The purpose of inserting the `interval of lag/,hereinbefore referred to, is to prevent the last impulse of a signal from blending with the start impulse of the next succeeding' signal in order to allow .time for the balance to be locked at the end of each signal and started again in the same phase position. When the machine is not'operated at its maximum speed, a natural lag will be produced between successive signals due to the pauses of the operator. When the machineis operated at its maximum speed, a

period of lag is automatically produced by causing ay cam 82 to rotate a certain amount after the escapement shaft 41 has cometo rest at the end of a signal interval, thereby causing the bottom of start control lever 14 to remain cocked to the'iight (Fig. 12) notwithstandingthe upper end of lever 11 has been moved'from behind it.

Cam82 is fast .upon a square hub ortion 83fof a sleeve 83 (Figs. ,15 -and 16) rotatably mounted on sleeve 64.- .lso fast on .sleeve 83 isa steel disc 84,.the inner face, of which lies againsta floating .fibre friction disc 85 inserted between disc 84 and a vface, of gear 62. This arrangement is such tha'tunless sleevell83" is restrained, it. will rotate with gear 62.hy.po'wer transmitted through friction. discs .84 85,'a'nd may thus. continue tof'rotate after shaft 41 lis stopped. lNormalr ly, however, 'sleeve 83, and therefore cani 82,'

are prevented from rotating by' a projec-v tion'86on a holding paivl v87 (Figs. 19 and .14) engagingwith either shoulder 88'or-89 of acam 9() also fast on said'sl'eeve.

- cause pawl 87 to release its holding projecution 86 from shoulder 88 of cam 90, Where upon said cam and its sleeve 83 VWill be released and rotate from power derived from the VJfriction Vclutch shown in Fig. 15. YVhen the drop of portion 91 of cam 93 passes lip 94 of pawl 87, stop 86, under the action of spring 87', will loel placed in positionto be engaged by ashoulder 95 of cam' 90, and by doing so will stop the rotation ofsleeve 83.

angular distance from shoulder 88 to shoulder 95 ofcam 90 (see Fig. 19), before shaft 41 completes .a half revolution. Then, by the time that the escapement shaft has com pleted its 'half rotation, elevated part 92 of cam 93 will occupy the same position relative to lip94 of the holding paWl 87 as does the eicx ated portion 91 in Fig. 18` thereby releasing` stop 86 from vshoulder 95. This willallow sleeve 83 to again take` up its rotation. Stop 86, however, is at this time shifted only farv enough to clear shoulder 95, but not far enough 7to clear shoulder 89 of cam 90, which latter shoulder engages stop 86 and arrests the rotation of sleeve 83 and consequently the rotation of cam 82. In rotating the angular distance from shoulder 95 to 89, however, which, it Will be noted,

takes place after shaft 41 has stopped its rotation, one of the high parts 97 of cam 82 passes extension' 96v on lever 14,Whereupon 'if a key is depressed at that time, lever 14 "will drop from said high part under the aetion of spring 15, and extension 16 on said lever acting on start lever 17, will cause the latter to turn on cam 19 as a fulcrum and sendthe start impulse as described, but delayed for an interval eqiuvalent to the time ofrotationrof slovv start sleeve 83 after the.

come -to rest at the end 'the lastimpulse period ,ofrthe signal inter- ,.val, 'and this is effected by mechanism shown most cleariysin Figs. 10 and 11. Directly after the' sion1 'start sleeve 83 commences to rotate, a` cam98 fast thereon starts into rotation from theposition shown in Fig. 11, and alloWs a vertically movable slide 99 to drop under the pull of a spring 100i ln doing so,.a knife edge 101, carried by saidlslide per edge,y of all the slide bars 6h56?, ishsent into engagement with -either 'of two notehes l102er 103 of said bars and. locks them against operation.until after the end ofthe last impulse .period ofia signal. Thev keys are unlockedat, the end of a signal by one Aand extending transversely vacross the upof the Vhigh parts of cam 98 again lifting slide 99. This slide is mounted in slots in yguides' 73 and '74 and is provided with an extension or arm 194 upon which cam 98 operates. 'Y

Tn descending, knife edge 101 engages slots102 of the operated bars, and slots 103 'of the unoperated bars, as .Will'be'4 readily seen. The advantage of operating cam "98 from the s'lmv start instead of from shaft 141 isvthat it prevents the possibility of the Sleeve 83, therefore, will have rotated the` signal. '.By the present arrangement, the

keys are completely locked v`until after the e impulse is completed.

i Motor cuto.'

The automatic cut off, for" use on way Wires whereby when the line is not in use all the motors 47 are automatically stopped and automatically started when lthe line is opened at any point, is shown most clearly in Figs. 3, 4, 9, 10, 23 andY 24, and com,-

' prises, vamongst other parts, a Worm 630 near one end of shaft 54, which is constantly driven by the motor of the machine. This 'Worm is adapted to at times engage with a tip 631 formed on an arm 632 fast to a shaft `A 633 adapted to 'rotate and slide longitudinally in the cont-act block 23A. Fast to the other end of this shaft is an arm 634, one end of which extends into aslot 635 of lever which'is pivotally connected to a swinging arm 636 having an extension 6 37 which is held, under tension of spring 638, against the periphery of cam 639 fast on the escapement shaft 41 (see Fig. 4.) Shaft 633 carries tension 637 to shift arm 33 to the right (Fig. i

4).- This permits shaft 633 to rotate underY the action oftorsional spring 644 in such direction as to bring tip 631 of arm 632 into engagement with worm 630 whereupon shaft 633 will beshifted to the right as vworm 630 continues its rotation. When-the end of a signal is reached, extension 637 on arm 33 will drop into one of the depressions in-cam 639, thus acting through arm 33, and arm 634 to remove' tip 631 from engagement with worm 630, thus stopping the movement of shaft 633 to the right. This shifting of shaft 633'- is not suiicient, however, to remove contact sleeve 640 from engagement- 1' with brushes 642 and 643. When the tip 631 has been Withdrawn from worm 630 as described, shaft 633 is pushed to the left (Fig. 10) under the extensional ten'sion of spring 644 to its starting point. However, if the circuit of magnet 28 is continuously closed, as for example, by the closing of one of the line switches 626-629r (Fig. 22), the armature arm 31 of said magnet (see Fig. 4), will continuously back up extension 32 on arm 33,

thereby preventing the movement of said arm to the left when a depression of camv639 reaches extension 637. )This shifts shoulder 645 of arm 33 in such direction as to permit spring 644 to continuously hold .the tip of armA 632 in engagement with worm 630.v Shaft 633 will, thereby be shifted4 so far to the right (Fig. 24) that the brushes 642 and 643 will be brought into engagement with insulating bushin 641 and thereby break the motor circuit. I then the circuit, including magnet 28 `is opened, as, for example, by

opening any oneof the line switches 626-629 (Fig. 22), arm 31 will drop, thus permitting lever 33 to be drawn t0 the lef/t and thereby acting through shoulder 645 and arm4 634 to rotate shaft 633 in such direction as to remove tip 631 of arm 632 from worm 630, whereupon shaft 633- will be shifted to the left (Fig. 10) by spring 644 and contact sleeve 640 again broughtv into engagement with brushes 642 and 643, thus again completing lthe motor circuit.

By the mechanism just described whenever signals 'are sent over the lline by closure of the contacts 26-27 the motor circuit remains closed, but when the line is closed for/"a greater length of time than whenany/signal 1s sent by 'contacts 26-27 e. g.by the closing of switch 626 the motor is stopped, but is again started as soon as the line is opened. What I claim is: y l. vIn a telegraph transmitter, means for transmitting an invariable starting impulse, means to transmit thereafter a series of varying impulses, a shaft adapted to operate the means for' transmitting the varying impulses, timing means to control the motion of said shaft, and a second shaft whose rate of motion is independent of said timing means to control the means for transmitting the invariable starting impulse.

2. In a transmitter, a keyboard,'a pair of contacts, means l'to cause said contacts to transmit a series of electrical impulses, varying according to thev signal to be transmitted, means to cause said contacts to transmit an impulse invariably precedin thevarying impulses foreach signal, sai second mentioned means includingmeans tending to close said contact,s-andftwoA devices to i prevent. saidlclsure, one of, said'vv devices aeting to prevent the operationoflsaid v'Contact l closing means until a certaininterval' after the completion of the preceding signal.,v` and the second of said devices acting top'event the operation of said .contact closing means except when a key of saidkeyboard is oper-` ated.

motor to drive the sanf`1ea` switch vtocontrol vthe motor, a magnet, .means operated ,byv

said magnet to start thetransmitter' into operation at the beginning? of each signal, automaticmeans to stop t the end of each signal, andjmean's also controlled by said magnet to operatethe switch.

3. In `a telegraph transmitter,anelectric e transmitter *atY v.

4. A telegraph transmitter'comprising a plurality of selectable members, means'for moving said members in predetermined combmataons, a member common to said'means and. `itiaovable upon the operation thereof, a

Contact spring, .and a pivoted lever 'operable upon the movement of said common-mem-l contact spring. i I

5. A telegraph transmitter comprising a plurality of selectable members, keys for moving said members in predetermined combinations, a membercommonY tov said keysand movable upon the operationiof any one thereof, a contact spring,- and a pivoted lever voperable upon the movement of said common member for controlling the actuation of -said contact spring.

6. A telegraphl transmitter comprising a plurality of selectable. members, keys for.

lio

ber for controlling the actuatioirof said movingsaid members in predetermined combinations,' a vmember common to said keys Oand-movable .upon the operation of any one thereof,"a contact spring, a lever operable upon the movement of said common member for controlling the actuation of saidcontact' ly'spr'mg, and means operated subsequently to etfeet tbe restoration ot said eontaet spring.

7. A telegraph transmitter comprising a plurality of selectableV members` keys for moving said members in' predetermined rombinations, a member common to said keys and movable upon the operation of any one thereof, a Contact spring` a lever operable upon'tbe movement ot' said Common member for Controlling the actuation of said contact spring, and mechanically operable means l'or subsequently effecting the` restoration ot said Contact spring.

8. A telegraph transmitter comprising a plurality ot' selectable members`r keys 'tor moving said members in predetermined (fombinations` a member eommon to said keys and movable upon the operation ot' any one thereof, a Contact spring` a lever operable .upon the movement otfsaid common member Jfor controlling the actuation ot said contact spring, and a cam eleetive subsequent to the movement of said common member for permitting the restoration ot said contact spring.

9. A telegraph transmitter Comprising a plurality otlseleetable members, keys 'for moving said members in predetermined com- .binations, a member common to said keys A and movable upon the operation of any one thereofVaav single Contact spring, a plunger operatively assoelated with said Contact springs, and a pivoted lever operated Vupon the movement of said common member for Controlling the actuation of said plunger to `tact spring and said common member and fulerumed on said cam upon the movement of said Common member tor Controlling the a tuation ot said Contact spring.

1l. telegraph transmitter Comprising aplurality ot selectable members, keys for moving said members in predetermined combinations. a member Common to said'keys and movable upon the operation ot' any one thereof, a single Contact spring, a cam, a lever operatively associated With said contact spring and said common member and fulerumed on said cam upon the movement ot said Commonmember tor controlling the actuation ot said 'contact spring. and mechanical means arranged to subsequently effeet the movement ot said lever whereby said Contact spring is restored to normal.

ln testimony whereof I aflix my signature.

LOUIS M. POTTS. 

